The invention refers to a driving device for a device for the local puncturing of a skin, particularly for the application of permanent make-up or a tattoo, and a method for operating the driving device.
Devices for the local puncturing of a skin are used, for example, for applying permanent make-up or a tattoo on human or animal skin and normally comprise a driving device with drive means for producing a repetitive thrust movement that is used in a module, coupled to the drive means, for the retraction and extension of puncturing means in order to puncture the skin, onto which the permanent make-up or the tattoo is to be applied. The puncturing means are normally a needle or a needle system that comprises several needles. After puncturing the skin, a coloring material routed along the puncturing means to the puncturing location can penetrate the skin surface. Such devices are described, for example, in the document U.S. Pat. No. 6,345,553.
When puncturing the skin to be treated, the thrust movement of the needle/of the needle system is confronted with a resistance force by the skin constituents. This resistance force depends on the individual characteristics of the skin in the surface area to be punctured. With known devices for applying permanent make-up or a tattoo, and with the help of a selection switch, a pre-specified repetition or repeating frequency of the repetitive/repeating thrust movement and subsequently the frequency of the skin puncturing per time unit can be stipulated, which is maintained at a constant level independent of the resistance force acting against the repetitive thrust movement. This is performed by re-regulation of the current/voltage values applied to the drive means for the purpose of maintaining a constant repetition frequency, even if there is a change in the resistance force resulting from changed skin characteristics. If such a constant maintenance of the repetition frequency is not envisaged, a drop of the repetition frequency can occur as a result of the increased resistance.
A skin area where an increased resistance force acts against the puncturing is described as a “harder skin”. During the transition into such a skin area, a non-uniform color deposition for the permanent make-up or for the tattoo can occur.
In the document U.S. Pat. No. 5,976,167, a needle device for the treatment of chronic muscle pains is described. The needle device comprises a needle for the intra-muscular stimulation as well as a thrust tool for accommodating the needle. With the help of a motor, the needle is put into a repetitive thrust movement by means of the thrust tool.
The subject-matter of the document U.S. Pat. No. 5,054,339 is the supply of tattooing color material from a vessel to a tattooing needle. The supply velocity of the color material to the needle is controlled by a pump.
The documents U.S. Pat. No. 4,782,725 and U.S. Pat. No. 4,671,277 each describe a tattooing device where the velocity and/or the repetition frequency of the thrust movement of the tattooing needle is controlled. The control is performed manually.
Finally, with one tattooing device described in the document U.S. Pat. No. 5,471,102, the repetition frequency is stipulated on the basis of switching parameters of a circuit arrangement controlling the needle movement.